FN Archimer Export Format PT J TI Lessons from the past: investigating historical data from bluefin tuna fisheries BT AF FROMENTIN, Jean-Marc AS 1:; FF 1:PDG-DOP-DCM-HMT-RHSETE; C1 IFREMER, Ctr Rech Mediterraneen & Trop, F-34203 Sete, France. C2 IFREMER, FRANCE SI SETE SE PDG-DOP-DCM-HMT-RHSETE IN WOS Ifremer jusqu'en 2018 IF 4.489 TC 54 UR https://archimer.ifremer.fr/doc/2009/publication-6425.pdf LA English DT Article DE ;Thunnus thynnus;Retrospective analysis;Population structure;Migration patterns;Fisheries collapse AB In 1963, the leading fisheries targeting Atlantic bluefin tuna (Thunnus thynnus) in the Norwegian Sea and North Sea suddenly collapsed without any warning. Little is known about this collapse and several hypotheses have been put forward, such as changes in migratory routes, recruitment failure or eradication of a sub-population: all of these hypotheses could result from natural causes and/or from overfishing. To help explain this mysterious event, an original data set of the main bluefin tuna fisheries of the 20th century, including total catch and size composition of the catch, has been compiled and analysed. The results reveal a strong and unambiguous link between the Nordic purse seine and Spanish trap fisheries during the 1950s and 1960s. However, this link vanished during the 1970s. In addition, the North-west Atlantic and Mediterranean trap fisheries appeared also to be partially connected to the Nordic fisheries. During the 1950s and 1960s, the main migration routes of bluefin tuna were probably from the Mediterranean spawning grounds and from the West Atlantic coasts to the Norwegian coast and North Sea, which were probably a key feeding ground at that time. The analyses also lead to the conclusion that interactions between environmental, trophic and fishing processes have probably affected bluefin tuna migration patterns which would have finally caused the Nordic fisheries collapse. This retrospective analysis finally leads to an original - albeit more speculative - hypothesis concerning Atlantic bluefin tuna population structure, therein conjectured as an assemblage of at least three sub-populations. PY 2009 PD JUL SO Fish and Fisheries SN 1467-2960 PU Wiley / Blackwell VL 10 IS 2 UT 000266024600006 BP 197 EP 216 DI 10.1111/j.1467-2979.2008.00311.x ID 6425 ER EF